Seismic response mitigation of a complex shape steel frame-concrete core tube composite structure considering multi-dimensional earthquakes

摘要

Employing a case of Ningxia TV Tower (NXTVT) as the background, the three-dimensional (3D) finite element model of NXTVT is established by resorting to SAP2000 software. The shape of NXTVT resembles a small bottom, large top, and slender-waist-middle vase. Likewise, its floors are arranged discontinuously, thus leading to the uneven distribution of the structural mass and stiffness. Hence, there is a need of a high demand of seismic performance in the design of this structure. Firstly, the dynamic characteristics of the structure is analyzed and investigated. Then, the multi-dimensional seismic responses of the structure under the operating base earthquake (OBE) with a return period of 50 years are analyzed by use of both the response spectrum method and FNA time history method. Finally, the time history analysis of NXTVT with the nonlinear fluid viscous dampers (FVD) is carried out to evaluate the seismic response mitigation performance of FVD to this structure under the multi-dimensional earthquakes, thus providing a reference for the seismic response mitigation design of this project.